Jay L. Posted July 11, 2013 Report Share Posted July 11, 2013 When trying to calculate the port length it asks for height and width of the port. How come if you reverse the height and width measurements, it changes the port length? It's the same sq. in./cu. ft.? Link to comment Share on other sites More sharing options...
bkolfo4 Posted July 11, 2013 Report Share Posted July 11, 2013 Because it is calculating as a slot port and is subtracting 1/2 the width from the length for end factor correction. Current system: 1997 Blazer - (4) Customer Fi NEO subs with (8) American Bass Elite 2800.1s Previous systems: 2000 Suburban - (4) BTL 15's and (4) IA 40.1's = 157.7 dB at 37 Hz. 1992 Astro Van - (6) BTL 15's and (6) IA 40.1's = 159.7 dB at 43 Hz. Link to comment Share on other sites More sharing options...
Joe X Posted July 11, 2013 Report Share Posted July 11, 2013 Post pics of the calculator output showing what you mean. Link to comment Share on other sites More sharing options...
Jay L. Posted July 11, 2013 Author Report Share Posted July 11, 2013 I've got a odd shaped port I'm trying to get an idea of how long it's going to be before I get to much farther. Im not using a box program, just a port calculator. Whats considered height and width? A port up box wouldn't have a "height". Sorry for the crap pic, if you look closely at the top center, you can see the shaded portion that is the port area... Link to comment Share on other sites More sharing options...
Jay L. Posted July 12, 2013 Author Report Share Posted July 12, 2013 So should the measurement I put in the height box be the longer measurement? Link to comment Share on other sites More sharing options...
Joe X Posted July 12, 2013 Report Share Posted July 12, 2013 If the port has an irregular shape like it seems it has then you need to calculate that area, if you are using Torres which does not support irregular shaped ports areas the I would recommend setting the height nearly to around the actual height you are using and then calculate for a width that matches the irregular shaped area you calculated so: port width = port height / irregular shaped area calculation result. Fill in the width and height you have calculated and then since the baffle width and height are also fixed, you will have left to play with the depth of the box and the length of the port. Link to comment Share on other sites More sharing options...
Jay L. Posted July 12, 2013 Author Report Share Posted July 12, 2013 I think Im following you. The most port area I can get is 248". 248/16 cu. gives me 15.5 in./cu. The biggest portion of the port is 10" tall, so what I did was put 10" for height, and 24.8" for width. That gave me "x" port length. Then I put 24.8" on height and 10" for width and that gave me a substantially different number. Im using the calculator on car stereo. com Im still undecided on how much port area to go with, until I can see what the correct lengths would be for several different port areas. Thanks for the help so far! Link to comment Share on other sites More sharing options...
Jay L. Posted July 13, 2013 Author Report Share Posted July 13, 2013 Which way is the correct way? The port calculator only knows the cu. ft. of the encloser and sq. in. of port. What if I had a tall and narrow driver side port, or a wide and short bottom port? Wouldn't the end factor corrections be different? Link to comment Share on other sites More sharing options...
Joe X Posted July 13, 2013 Report Share Posted July 13, 2013 The end correction is taken from what you enter as "width" so enter the lesser dimension of your port there whichever that is. The other problem is that it asks for the net volume which in turn changes if you change the dimensions of the port so keep that in mind as well. Link to comment Share on other sites More sharing options...
Jay L. Posted July 13, 2013 Author Report Share Posted July 13, 2013 Thanks Joe. Link to comment Share on other sites More sharing options...
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